Multilayer printed wiring board and method of manufacturing the same
AssigneeCMK Corporation
InventorEiji Hirata
Life of this patent
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Abstract
This invention provides a multilayer printed wiring board having flat via holes. This is a multilayer printed wiring board formed by alternately laminating multiple metal foils and insulating layers, in which an interlayer connection via pad provided in a first insulating layer, a wiring circuit and an interlayer connection via bottom pad of a second insulating layer are provided in the same surface layer and at least the interlayer connection via pad and the interlayer connection via bottom pad of the second insulating layer have the same thickness.
Claims13
A multilayer printed wiring board formed by alternately laminating multiple insulating layers and metal foils, in which an interlayer connection via pad provided in a first insulating layer, a wiring circuit and an interlayer connection via bottom pad of a second insulating layer are provided in the same surface layer and at least the interlayer connection via pad and the interlayer connection via bottom pad of the second insulating layer have the same thickness.
A method of manufacturing a multilayer printed wiring board, comprising the steps of:
- preparing an insulating substrate, the front and back surfaces of which have metal foil and forming a circuit by laminating a first insulating layer and metal foil at least on one surface of the insulating substrate;
- forming a nonthrough hole for interlayer connection;
- forming a barrier layer substantially in the whole area;
- forming a metal coating substantially in the whole area;
- forming an etching resist in an interlayer connection via pad and an interlayer connection via bottom pad of an interlayer insulating layer of an upper layer;
- etching the metal coating thereby to remove an excess of metal coating;
- exfoliating the etching resist;
- removing an exposed barrier layer;
- forming a second insulating layer and a metal layer;
- forming a circuit;
- forming a nonthrough hole for interlayer connection;
- forming a barrier layer substantially in the whole area;
- forming a metal coating substantially in the whole area;
- forming an etching resist in an interlayer connection via pad for circuit formation in an outermost layer;
- removing an excess metal coating;
- exfoliating the etching resist;
- and
- removing the barrier layer.
A method of manufacturing a multilayer printed wiring board, comprising the steps of:
- preparing an insulating substrate, the front and back surface's of which have metal foil and forming a circuit on the insulating substrate;
- forming a nonthrough hole for interlayer connection;
- forming an electroless metal coating substantially in the whole area;
- forming an electrolytic metal coating substantially in the whole area;
- forming an etching resist in an interlayer connection via pad and an interlayer connection via bottom pad of an interlayer insulating layer of an upper layer;
- etching the metal coating thereby to remove an excess of metal coating;
- exfoliating the etching resist;
- further forming an insulating layer and a metal layer;
- forming a circuit;
- forming a nonthrough hole for interlayer connection;
- forming an electroless metal coating substantially in the whole area;
- forming an electrolytic metal coating substantially in the whole area;
- forming an etching resist in an interlayer connection via pad for circuit formation in an outermost layer;
- removing an excess of metal coating;
- and
- exfoliating the etching resist.
Dependencies are inferred from the claim text.